382 ALASKAN GLACIER STUDIES There are many cirques in the high, northern part of the island, showing that there has been extensive local glaciation here. The southern part of the island is plateau-like, having no rugged topography but a broad, rolling upland with rounded summits, the highest of which are Signal Mountain, 1546 feet high, on the southwestern end near Port Etches, some elevations of 2260 feet near the middle of the island, and summits 1709 feet high near the eastern end. This southern half of the island has extensive cirques, a number of conspicuous ones cutting into the plateau-like upland, with valleys extending northward to Port Etches (PI. CLXXXIIE). GLACIERS or EASTERN PRINCE WILLIAM SOUND Among the fiords of eastern Prince William Sound, Valdez Arm and Port Valdez in the northeastern corner have already been described (Chapter XIII). The fiords south of this are Port Fidalgo, Port Gravina, Sheep Bay, Simpson Bay, Orca or Cordova Bay, and t)rca Inlet. Port FidalgoTopography. Port Fidalgo, which has also been called Fidalgo Bay, is the largest of the fiords on the eastern side of Prince William Sound, south of Valdez Arm. It is 25 to 38 miles long, as shown by different maps, and 5£ miles wide at the mouth decreasing to two miles or less inside the fiord. Its general course from Prince William Sound is east-northeast, but near the head it turns at a sharp angle and trends southeastward. There are a number of tributary bays, including Snug Corner Cove, Two Moon or Bowie Bay, Irish Cove, and Whalen Bay on the southern side, and Fish, Landlocked, and Boulder Bays on the north. The latter is also connected with Valdez Arm through Tatitlek Narrows, behind Bligh Island, which lies north of the entrance to Port Fidalgo. Goose Island lies south of the entrance. This fiord extends far back into the Chugach Mountains. Near the entrance the fiord walls rise 1600 to 3000 feet close to the water's edge, back of a narrow fringe of foreland, but there are many peaks rising to greater heights, among them being Copper Mountain, 8830 feet, and Mt. Denson, 5886 feet. There has been no detailed topographic survey in the eastern half of Port Fidalgo, but the fiord walls there seem to be still steeper and there are peaks rising to 8721 feet, 5558 feet, and 6182 feet, while there are many higher ones in the Chugach Mountains still farther to the east. Contracted Condition of Glaciers. The glaciers of this fiord are very small and long ago receded far into the mountains, from which they have not projected far enough to be tidal since before 1778. A great many mountains about the eastern end of Port Fidalgo are snow-capped throughout the summer, and there are probably many moderate-sized glaciers, besides the few small ones visible from the entrance to the fiord. The only ones thus far shown upon a map are the glacier on Mt. Denson and a little ice tongue terminating half a mile or so northeast of the head of Port Fidalgo. Doubtless the unexplored mountain valleys contain fair-sized glaciers, fed by the extensive snowfields of this portion of the Chugach Mountains. This fiord was visited by Cook in 1778, Meares in 1786, Dixon in 1787, Fidalgo in 1790, and Johnstone in 1794, but none of these explorers mention floating ice, from which we infer that there was no tidal glacier within it in the latter part of the eighteenth century. Their descriptions of the snow-capped mountains suggest conditions not unlike those at present.